1. Field of the Invention
This invention relates to communication. In particular, the invention relates to multi-channel receivers.
2. Description of Related Art
A typical multi-channel broadcast signal has a number of channels occupying allocated bandwidths. A receiver equipment receives a multi-channel signal and can generate the output for each channel one at a time. A channel selector in the receiver equipment can only allow the selection of one channel output at a time. For example, a television (TV) receiver allows the user to select a TV channel to be displayed on the screen.
In many cases, it is desirable to be able to select many or all channels in the multi-channel signal for multiple purposes. For example, a user may want to watch a sport event while taping a TV show simultaneously. Traditional techniques to provide multiple channel outputs require redundant hardware with separate tuner and channel selectors. These techniques result in hardware complexity and difficulty in selecting the desired channel outputs.
Therefore there is a need in the technology to provide a simple and flexible method to generate multiple channel outputs simultaneously using a single receiver system.
The present invention is a method and apparatus to generate one or more channel outputs from an input signal having N channels. The input signal is filtered by a polyphase filter to generate N filtered signals. The one or more channel outputs are extracted from the N filtered signal based on one or more phases corresponding to the one or more channel outputs.